JP7547554B2 - Sulfur-containing compounds and polymers and their use in electrochemical cells - Patents.com - Google Patents

Description

RELATED APPLICATIONS This application claims priority under applicable law to Canadian Patent Application No. 2,981,012, filed October 2, 2017, the contents of which are incorporated herein by reference in their entirety for all purposes.

TECHNICAL FIELD This application relates to the field of polymers and oligomers for use as electrochemically active materials in positive electrodes, as solid polymer electrolytes (SPEs) or as additives to electrolytes, especially in lithium batteries.

Awareness of the global environment has inspired many scientists to find answers to the problem of greenhouse gases and their impact on the planet. As we know that transportation plays a major role in greenhouse gas emissions, electrifying transportation is definitely part of the solution to global warming. Therefore, it is important to design new battery materials that are more environmentally friendly, more affordable, safer and offer performances (such as autonomy and power) close to those of fossil fuels.

Organic cathodes are prime candidates for the production of batteries capable of meeting the demands of energy storage. The advantage of these materials is that their synthesis temperatures are significantly lower than those of intercalation materials (Armand et al., Nature, 2008, 451, 652). Moreover, they are composed of abundant elements and offer excellent electrochemical performance (Le Gall et al., Journal of Power Sources, 2003, 316-320). On the other hand, their biggest drawback is related to the dissolution of the active material into the electrolyte, which greatly affects the stability of the battery (Chen et al., ChemSusChem., 2008, 1, 348-355). Electrochemically active organic polymers can make it possible to inhibit or reduce the dissolution of the active material in order to obtain more cyclable materials (Zeng et al., Electrochimica Acta, 2014, 447-454).

Elemental sulfur is also a candidate for the production of batteries with high energy density. Indeed, lithium-sulfur (Li-S) batteries are very promising given the advantages offered by this element, namely its large capacity of 1675 mAh/g and its great abundance. The latter is attributed to the fact that sulfur is a by-product of petroleum refining (Hyun et al., ACS Energy Letters, 2016, 1, 566-572). However, Li-S batteries also have several drawbacks, including the dissolution of polysulfides (Li ₂ S _x , x=4-8) that are generated by the reduction of sulfur during cycling. Moreover, once dissolved, polysulfides are involved in a phenomenon called the "shuttle effect," which destabilizes the lithium surface (anode). This phenomenon leads to reduced stability and low coulombic efficiency (Zhou et al., J. Am. Chem. Soc. 2013, 135, 16736-16743).

One strategy used to solve this problem involves the encapsulation of sulfur particles. For example, Zhou et al. (J. Am. Chem. Soc. 2013, 135, 16736-16743) coated sulfur with polyaniline (PANI) to immobilize the polysulfides inside this shell. Encapsulating the sulfur makes it possible to increase the stability of the battery. However, the addition of this element limits the amount of sulfur in the active material to only 58% by weight; that is, 42% by weight of this material consists of electrochemically inactive material, thereby reducing the charge density of the electrode material. With this strategy, coulombic efficiencies of over 97% can still be obtained, but the long-term cyclability is still limited.

The synthesis of carbon-sulfur composites has also been presented. For example, Wang et al. (Journal of Power Sources, 2011, 7030-7034) synthesized a graphene-sulfur composite. This new material makes it possible not only to increase the specific electrical conductivity, but also to achieve an initial capacity almost equal to the theoretical value. However, the presence of graphene does not suppress the phenomenon of polysulfide dissolution, and this material has a capacity loss comparable to that of sulfur itself.

Copolymerization of elemental sulfur with one or more organic monomers has also been investigated to obtain sulfur-rich polymers. When sulfur is heated above 159° C., the (S ₈ ) ring opening occurs, which generates diradicals that can undergo radical polymerization. Chung et al. (Nature Chemistry, 2013, 5, 518-524) developed sulfur-rich copolymers for Li—S batteries. Elemental sulfur was copolymerized with different percentages of 1,3-diisopropenylbenzene (DIB) by inverse vulcanization. The copolymerization makes it possible to create a matrix that can limit the dissolution of polysulfides. Their electrochemical results show excellent coulombic efficiency and good capacity retention. However, as presented above, the organic monomers used are electrochemically inactive, which leads to the presence of inactive masses and, consequently, to a reduced energy density.
Thus, for example, there is a need for the development of new electrode materials that combine some of the advantages of previous materials while eliminating at least one of their disadvantages.

Armand et al., Nature, 2008, 451, 652 Le Gall et al., Journal of Power Sources, 2003, 316-320 Chen et al., ChemSusChem., 2008, 1, 348-355 Zeng et al., Electrochimica Acta, 2014, 447-454 Hyun et al., ACS Energy Letters, 2016, 1, 566-572 Zhou et al., J. Am. Chem. Soc. 2013, 135, 16736-16743 Wang et al., Journal of Power Sources, 2011, 7030-7034 Chung et al., Nature Chemistry, 2013, 5, 518-524

（式中、
Ａは、電子の非局在化を許容する不飽和基、例えば、置換または非置換のアリールおよびヘテロアリール基、ならびにそれらの縮合または非縮合多環式対応物から選択され；
Ｒは、直鎖または分岐鎖Ｃ_２－６アルキレン、直鎖または分岐鎖Ｃ_２－６アルキレンオキシ、直鎖または分岐鎖Ｃ_２－６アルキレングリコール、直鎖または分岐鎖Ｃ_２－６アルキレンオキシＣ_２－６アルキレン、直線状または分岐鎖ポリ（Ｃ_２－６アルキレングリコール）、Ｃ_６－１２アリーレン、Ｃ_３－１２シクロアルキレン、Ｃ_５－１２ヘテロアリーレン、およびＣ_３－１２ヘテロシクロアルキレンから選択される置換または非置換有機連結基であり；
ｍは、ポリマーリンクのジスルフィド結合に挿入された硫黄原子の平均数を表し、ゼロであり得ず、すなわち、ｍ＞０、例えば０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４であり；かつ
ｎは、ポリマー中の単位の平均数を表し、例えば、ｎは２～５００、または５～３００の範囲内であり得る）
に関する。 According to a first aspect, the present disclosure relates to a polymer of formula I:

(Wherein,
A is selected from unsaturated groups that allow for electron delocalization, such as substituted or unsubstituted aryl and heteroaryl groups, and their fused or non-fused polycyclic counterparts;
R is a substituted or unsubstituted organic linking group selected from linear or branched C _2-6 alkylene, linear or branched C _2-6 alkyleneoxy, linear or branched C _2-6 alkylene glycol, linear or branched C _2-6 alkyleneoxy C _2-6 alkylene, linear or branched poly(C _2-6 alkylene glycol), C _6-12 arylene, C _3-12 cycloalkylene, C _5-12 heteroarylene, and C _3-12 heterocycloalkylene;
m represents the average number of sulfur atoms inserted into the disulfide bonds of the polymer links and cannot be zero, i.e., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4; and n represents the average number of units in the polymer, e.g., n can be in the range of 2 to 500, or 5 to 300.
Regarding.

（式中、Ｒ、ｍおよびｎは、本明細書に定義される通りである）
のポリマーである。 According to one embodiment, A is selected from benzene, naphthalene, perylene and biphenyl groups. For example, A is a benzene group and the polymer has formula I(a):

wherein R, m, and n are as defined herein.
It is a polymer of.

According to another embodiment, R is selected from the group consisting of benzene, ethylene, propylene, poly(ethylene glycol), poly(propylene glycol), and copolymers of ethylene glycol and propylene glycol.

（式中、ｍおよびｎは、本明細書に定義される通りである）
によっても例示される。 An example of a polymer has formula I(b):

wherein m and n are as defined herein.
This is also exemplified by:

（式中、ＡおよびＲは、本明細書に定義される通りであり、ｍは、化合物のジスルフィド結合に挿入された硫黄原子の数を表し、例えば、ｍ＞０、例えば、０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４である）
に関する。 According to another aspect, the present disclosure relates to a compound of formula II:

wherein A and R are as defined herein, and m represents the number of sulfur atoms inserted into the disulfide bond of the compound, e.g., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4.
Regarding.

（式中、Ｒおよびｍは、本明細書に定義される通りである）
で表される。 An example of this compound is represented by formula II(a):

wherein R and m are as defined herein.
It is expressed as:

（式中、ｍは本明細書に定義される通りである）
によって例示される。 Another example of a compound has formula II(b):

wherein m is as defined herein.
As exemplified by:

According to another aspect, the present description relates to an electrode material comprising a polymer or compound as defined herein. For example, the electrode material further comprises a conductive material, a binder, or a combination of both. The electrode material may also comprise free elemental sulfur (S _x ).

According to one embodiment, the conductive material is selected from carbon black, Ketjen™ carbon, Shawinigan carbon, acetylene black, graphite, graphene, carbon fibers (e.g., carbon nanofibers (e.g., VGCF formed in the gas phase), etc.), carbon nanotubes, or a combination of at least two thereof.

According to one embodiment, the binder is a polymeric binder of polyether type, fluorinated polymer type, or water-soluble binder. According to one example, the polymeric binder of polyether type is linear, branched, and/or crosslinked, optionally including crosslinkable units, based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), or a combination of the two (or EO/PO copolymers). According to another example, the fluorinated polymeric binder is PVDF (polyvinylidene fluoride) or PTFE (polytetrafluoroethylene). Finally, examples of water-soluble binders include SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), or ACM (acrylate rubber), optionally including CMC (carboxymethylcellulose).

According to a further aspect, the present disclosure relates to a positive electrode comprising an electrode material as defined herein applied to a current collector.

According to a further aspect, the present description also relates to an electrolyte comprising a polymer as defined herein or a compound as defined herein. According to one embodiment, the electrolyte is a liquid electrolyte comprising a salt in a solvent. According to one alternative, the electrolyte is a gel electrolyte comprising a salt in a solvent and optionally a solvating polymer. According to a second alternative, the electrolyte is a solid polymer electrolyte (SPE) comprising a salt in a solvating polymer. For example, the polymer as defined herein or the compound as defined herein is an additive. Alternatively, the solvating polymer of the SPE is a polymer as defined herein or a compound as defined herein. According to another embodiment, the salt is a lithium salt. According to one embodiment, the electrolyte further comprises elemental sulfur, a binder, an additive or a combination of at least two thereof.

Another aspect refers to electrochemical cells comprising a cathode, an electrolyte, and an anode, where the cathode comprises an electrode material as defined herein. According to alternative embodiments, these electrochemical cells comprise a negative electrode, an electrolyte, and a positive electrode as defined herein. According to alternative embodiments, these electrochemical cells comprise a cathode, an anode, and an electrolyte as defined herein. The description also refers to lithium batteries comprising such electrochemical cells.

［式中、
Ａは、電子の非局在化を許容する不飽和基、例えば、置換または非置換のアリールおよびヘテロアリール基、ならびにそれらの縮合または非縮合多環式等価物から選択され；
Ｒは、直鎖または分岐鎖Ｃ_２－６アルキレン、直鎖または分岐鎖Ｃ_２－６アルキレンオキシ、直鎖または分岐鎖Ｃ_２－６アルキレングリコール、直鎖または分岐鎖Ｃ_２－６アルキレンオキシＣ_２－６アルキレン、直線状または分岐鎖ポリ（Ｃ_２－６アルキレングリコール）、Ｃ_６－１２アリーレン、Ｃ_３－１２シクロアルキレン、Ｃ_５－１２ヘテロアリーレン、およびＣ_３－１２ヘテロシクロアルキレンから選択される置換または非置換有機連結基であり；
ｍは、ポリマーリンクのジスルフィド結合に挿入された硫黄原子の平均数を表し、ゼロであり得ず、すなわち、ｍ＞０、例えば０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４であり；かつ
ｎは、ポリマー中の単位の平均数を表し、例えば、ｎは２～５００、または５～３００の範囲内であり得る］。
（項目２）
Ａが、ベンゼン、ナフタレン、ペリレン、およびビフェニル基から選択される、項目１に記載のポリマー。
（項目３）
前記ポリマーが式Ｉ（ａ）：

［式中、Ｒ、ｍおよびｎは項目１に定義される通りである］
のポリマーである項目１または２に記載のポリマー。
（項目４）
Ｒが、ベンゼン、エチレン、プロピレン、ポリ（エチレングリコール）、ポリ（プロピレングリコール）、およびエチレングリコールとプロピレングリコールの共重合体の基から選択される、項目１から３のいずれか一項に記載のポリマー。
（項目５）
前記ポリマーが式Ｉ（ｂ）：

［式中、ｍおよびｎは項目１に定義される通りである］
のポリマーである、項目４に記載のポリマー。
（項目６）
式ＩＩの化合物：

［式中、ＡおよびＲは、項目１、２および４のいずれか一項に定義される通りであり；ｍは、前記化合物のジスルフィド結合に挿入された硫黄原子の数を表し、例えば、ｍ＞０、例えば、０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４である］。
（項目７）
前記化合物が式ＩＩ（ａ）：

［式中、Ｒおよびｍは、項目６に定義される通りである］
の化合物である、項目６に記載の化合物。
（項目８）
前記化合物が式ＩＩ（ｂ）：

［式中、ｍは、項目６に定義される通りである］
の化合物である、項目６に記載の化合物。
（項目９）
項目１から５のいずれか一項に定義されるポリマー、または項目６から８のいずれか一項に定義される化合物を含む電極材料。
（項目１０）
硫黄元素をさらに含む、項目９に記載の電極材料。
（項目１１）
導電性材料、バインダー、または両方の組合せをさらに含む、項目９または１０に記載の電極材料。
（項目１２）
前記導電性材料が、カーボンブラック、Ｋｅｔｊｅｎ（商標）カーボン、シャウィニガンカーボン、アセチレンブラック、グラファイト、グラフェン、カーボンファイバー（例えばカーボンナノファイバー（例えば、気相で形成されたＶＧＣＦ）など）、およびカーボンナノチューブ、またはそれらの少なくとも２つの組合せから選択される、項目１１に記載の電極材料。
（項目１３）
前記バインダーがポリエーテル型のポリマーバインダー、フッ素化ポリマー、または水溶性バインダーである、項目１１または１２に記載の電極材料。
（項目１４）
前記ポリエーテル型のポリマーバインダーが直線状、分岐鎖、および／または架橋したものであり、ポリ（エチレンオキシド）（ＰＥＯ）、ポリ（プロピレンオキシド）（ＰＰＯ）、またはこれら２つの混合物（またはＥＯ／ＰＯ共重合体）に基づき、架橋可能な単位を必要に応じて含む、項目１３に記載の電極材料。
（項目１５）
前記フッ素化ポリマーバインダーが、ＰＶＤＦ（ポリフッ化ビニリデン）またはＰＴＦＥ（ポリテトラフルオロエチレン）である、項目１３に記載の電極材料。
（項目１６）
前記水溶性バインダーが、ＳＢＲ（スチレン－ブタジエンゴム）、ＮＢＲ（アクリロニトリル－ブタジエンゴム）、ＨＮＢＲ（水素化ＮＢＲ）、ＣＨＲ（エピクロロヒドリンゴム）、またはＡＣＭ（アクリレートゴム）であり、必要に応じてＣＭＣ（カルボキシメチルセルロース）を含む、項目１３に記載の電極材料。
（項目１７）
集電体に適用された、項目９から１６のいずれか一項に記載の電極材料を含む正極。
（項目１８）
項目１から５のいずれか一項に定義されるポリマー、または項目６から８のいずれか一項に定義される化合物を含む電解質。
（項目１９）
前記電解質が、溶媒中の塩を含む液体電解質である、項目１８に記載の電解質。
（項目２０）
前記電解質が、溶媒中の塩および必要に応じて溶媒和ポリマーを含むゲル電解質である、項目１８に記載の電解質。
（項目２１）
前記溶媒が、エチレンカーボネート（ＥＣ）、ジエチルカーボネート（ＤＥＣ）、プロピレンカーボネート（ＰＣ）、ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）、γ－ブチロラクトン（γ－ＢＬ）、ビニレンカーボネート（ＶＣ）、酪酸メチル（ＭＢ）、γ－バレロラクトン（γ－ＶＬ）、１，２－ジメトキシエタン（ＤＭＥ）、１，２－ジエトキシエタン（ＤＥＥ）、２－メチルテトラヒドロフラン、ジメチルスルホキシド、ホルムアミド、アセトアミド、ジメチルホルムアミド、ジオキソラン、アセトニトリル、プロピルニトリル、ニトロメタン、エチルモノグリム、トリメトキシメタン、ジオキソラン誘導体、スルホラン、メチルスルホラン、プロピレンカーボネート誘導体、テトラヒドロフラン、およびそれらの混合物から選択される極性非プロトン性溶媒である、項目１９または２０に記載の電解質。
（項目２２）
前記電解質が、溶媒和ポリマー中の塩を含む固体ポリマー電解質（ＳＰＥ）である、項目１８に記載の電解質。
（項目２３）
前記ポリマーまたは前記化合物が添加剤である、項目１８から２２のいずれか一項に記載の電解質。
（項目２４）
前記溶媒和ポリマーが、項目１から５のいずれか一項に定義される前記ポリマーまたは項目６から８のいずれか一項に定義される前記化合物である、項目２２に記載の電解質。
（項目２５）
前記電解質が、硫黄元素をさらに含む、項目１８から２４のいずれか一項に記載の電解質。
（項目２６）
前記塩がリチウム塩である、項目１９から２５のいずれか一項に記載の電解質。
（項目２７）
前記塩が、ヘキサフルオロリン酸リチウム（ＬｉＰＦ_６）、リチウムビス（トリフルオロメタンスルホニル）イミド（ＬｉＴＦＳＩ）、リチウムビス（フルオロスルホニル）イミド（ＬｉＦＳＩ）、リチウム２－トリフルオロメチル－４，５－ジシアノイミダゾレート（ＬｉＴＤＩ）、リチウム４，５－ジシアノ－１，２，３－トリアゾレート（ＬｉＤＣＴＡ）、リチウムビス（ペンタフルオロエチルスルホニル）イミド（ＬｉＢＥＴＩ）、テトラフルオロホウ酸リチウム（ＬｉＢＦ_４）、リチウムビス（オキサラト）ボレート（ＬｉＢＯＢ）、硝酸リチウム（ＬｉＮＯ_３）、塩化リチウム（ＬｉＣｌ）、臭化リチウム（ＬｉＢｒ）、フッ化リチウム（ＬｉＦ）、過塩素酸リチウム（ＬｉＣｌＯ_４）、ヘキサフルオロヒ酸リチウム（ＬｉＡｓＦ_６）、トリフルオロメタンスルホン酸リチウム（ＬｉＳＯ_３ＣＦ_３）（ＬｉＴｆ）、フルオロアルキルリン酸リチウムＬｉ［ＰＦ_３（ＣＦ_２ＣＦ_３）_３］（ＬｉＦＡＰ）、リチウムテトラキス（トリフルオロアセトキシ）ボレートＬｉ［Ｂ（ＯＣＯＣＦ_３）_４］（ＬｉＴＦＡＢ）、リチウムビス（１，２－ベンゼンジオラト（２－）－Ｏ、Ｏ’）ボレートＬｉ［Ｂ（Ｃ_６Ｏ_２）_２］（ＬＢＢＢ）およびそれらの組合せから選択される、項目２６に記載の電解質。
（項目２８）
前記電解質が、電解質バインダーをさらに含む、項目１８から２７のいずれか一項に記載の電解質。
（項目２９）
前記電解質バインダーが、ポリエーテル型のポリマーバインダー、フッ素化ポリマー、または水溶性バインダーである、項目２８に記載の電解質。
（項目３０）
前記フッ素化ポリマーバインダーがポリフッ化ビニリデン（ＰＶＤＦ）である、項目２９に記載の電解質。
（項目３１）
カソード、電解質、およびアノードを含む電気化学セルであって、前記カソードが、項目９から１６のいずれか一項に定義される電極材料を含む、電気化学セル。
（項目３２）
負極、電解質および項目１７に定義される正極を含む、電気化学セル。
（項目３３）
カソード、アノードおよび項目１８から３０のいずれか一項に定義される電解質を含む電気化学セル。
（項目３４）
負極、電解質および正極を含む電気化学セルであって、前記正極が項目１７に定義されるものであり、前記電解質が項目１８から３０のいずれか一項に定義されるものである、電気化学セル。
（項目３５）
項目３１から３４のいずれか一項に定義される電気化学セルを含むリチウム電池。 Finally, the present description refers to processes for producing the polymers and compounds defined herein, electrode materials, electrolyte materials, electrodes, electrolytes, and electrochemical cells containing them. The use of these electrochemical cells is also contemplated, more particularly in portable devices, such as mobile phones, cameras, tablets or laptops, in electric or hybrid vehicles, or in renewable energy storage.
In an embodiment of the present invention, for example, the following items are provided:
(Item 1)
Polymer of Formula I:

[Wherein,
A is selected from unsaturated groups that allow for electron delocalization, such as substituted or unsubstituted aryl and heteroaryl groups, and fused or non-fused polycyclic equivalents thereof;
R is a substituted or unsubstituted organic linking group selected from linear or branched C _2-6 alkylene, linear or branched C _2-6 alkyleneoxy, linear or branched C _2-6 alkylene glycol, linear or branched C _2-6 alkyleneoxy C _2-6 alkylene, linear or branched poly(C _2-6 alkylene glycol), C _6-12 arylene, C _3-12 cycloalkylene, C _5-12 heteroarylene, and C _3-12 heterocycloalkylene;
m represents the average number of sulfur atoms inserted into the disulfide bonds of the polymer links and cannot be zero, i.e., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4; and n represents the average number of units in the polymer, e.g., n can be in the range of 2 to 500, or 5 to 300.
(Item 2)
2. The polymer of claim 1, wherein A is selected from benzene, naphthalene, perylene, and biphenyl groups.
(Item 3)
The polymer has formula I(a):

[In the formula, R, m and n are as defined in item 1]
3. The polymer according to item 1 or 2, which is a polymer of the formula:
(Item 4)
4. The polymer according to any one of the preceding claims, wherein R is selected from the group consisting of benzene, ethylene, propylene, poly(ethylene glycol), poly(propylene glycol), and copolymers of ethylene glycol and propylene glycol.
(Item 5)
The polymer has formula I(b):

[wherein m and n are as defined in item 1]
5. The polymer according to claim 4, which is a polymer of formula:
(Item 6)
Compound of Formula II:

[wherein A and R are as defined in any one of items 1, 2 and 4; m represents the number of sulfur atoms inserted in the disulfide bond of the compound, e.g., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4].
(Item 7)
The compound has formula II(a):

[In the formula, R and m are as defined in item 6]
7. The compound according to claim 6, which is a compound of formula:
(Item 8)
The compound has formula II(b):

[In the formula, m is as defined in item 6]
7. The compound according to claim 6, which is a compound of formula:
(Item 9)
Electrode material comprising a polymer as defined in any one of items 1 to 5 or a compound as defined in any one of items 6 to 8.
(Item 10)
10. The electrode material according to item 9, further comprising elemental sulfur.
(Item 11)
11. The electrode material of item 9 or 10, further comprising a conductive material, a binder, or a combination of both.
(Item 12)
Item 12. The electrode material of item 11, wherein the conductive material is selected from carbon black, Ketjen™ carbon, Shawinigan carbon, acetylene black, graphite, graphene, carbon fibers (such as carbon nanofibers (e.g., VGCF formed in the gas phase)), and carbon nanotubes, or a combination of at least two thereof.
(Item 13)
13. The electrode material according to item 11 or 12, wherein the binder is a polyether type polymer binder, a fluorinated polymer, or a water-soluble binder.
(Item 14)
14. The electrode material according to item 13, wherein the polymer binder of polyether type is linear, branched and/or crosslinked and optionally comprises crosslinkable units based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), or a mixture of the two (or EO/PO copolymers).
(Item 15)
Item 14. The electrode material according to item 13, wherein the fluorinated polymer binder is PVDF (polyvinylidene fluoride) or PTFE (polytetrafluoroethylene).
(Item 16)
Item 14. The electrode material according to item 13, wherein the water-soluble binder is SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), or ACM (acrylate rubber), and optionally contains CMC (carboxymethyl cellulose).
(Item 17)
17. A positive electrode comprising the electrode material according to any one of items 9 to 16 applied to a current collector.
(Item 18)
9. An electrolyte comprising a polymer as defined in any one of items 1 to 5 or a compound as defined in any one of items 6 to 8.
(Item 19)
20. The electrolyte of claim 18, wherein the electrolyte is a liquid electrolyte comprising a salt in a solvent.
(Item 20)
19. The electrolyte according to claim 18, wherein the electrolyte is a gel electrolyte comprising a salt in a solvent and optionally a solvating polymer.
(Item 21)
21. The electrolyte according to item 19 or 20, wherein the solvent is a polar aprotic solvent selected from ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), gamma-butyrolactone (gamma-BL), vinylene carbonate (VC), methyl butyrate (MB), gamma-valerolactone (gamma-VL), 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 2-methyltetrahydrofuran, dimethylsulfoxide, formamide, acetamide, dimethylformamide, dioxolane, acetonitrile, propylnitrile, nitromethane, ethyl monoglyme, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, propylene carbonate derivatives, tetrahydrofuran, and mixtures thereof.
(Item 22)
20. The electrolyte of claim 18, wherein the electrolyte is a solid polymer electrolyte (SPE) comprising a salt in a solvating polymer.
(Item 23)
23. The electrolyte of any one of claims 18 to 22, wherein the polymer or the compound is an additive.
(Item 24)
23. The electrolyte of claim 22, wherein the solvating polymer is the polymer defined in any one of claims 1 to 5 or the compound defined in any one of claims 6 to 8.
(Item 25)
25. The electrolyte of any one of claims 18 to 24, wherein the electrolyte further comprises elemental sulfur.
(Item 26)
26. The electrolyte of any one of claims 19 to 25, wherein the salt is a lithium salt.
(Item 27)
The salt may be selected from the group consisting of lithium hexafluorophosphate (LiPF ₆ ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF ₄ ), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO ₃ ), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), lithium trifluoromethanesulfonate (LiSO ₃ CF _{3 27. The} electrolyte _{of claim 26} , wherein the _lithium fluoride is selected from _{lithium fluoride} , _...
(Item 28)
28. The electrolyte of any one of claims 18 to 27, wherein the electrolyte further comprises an electrolyte binder.
(Item 29)
29. The electrolyte of claim 28, wherein the electrolyte binder is a polyether type polymeric binder, a fluorinated polymer, or a water-soluble binder.
(Item 30)
30. The electrolyte of claim 29, wherein the fluorinated polymer binder is polyvinylidene fluoride (PVDF).
(Item 31)
17. An electrochemical cell comprising a cathode, an electrolyte, and an anode, wherein the cathode comprises an electrode material as defined in any one of claims 9 to 16.
(Item 32)
18. An electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode as defined in item 17.
(Item 33)
31. An electrochemical cell comprising a cathode, an anode and an electrolyte as defined in any one of items 18 to 30.
(Item 34)
31. An electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode, wherein the positive electrode is as defined in item 17 and the electrolyte is as defined in any one of items 18 to 30.
(Item 35)
35. A lithium battery comprising an electrochemical cell as defined in any one of items 31 to 34.

FIG. 1 shows the resulting percentage of capacity (mAh/g) and capacity retention as a function of cycle number for (A) Cell 1 (baseline) containing polyimide disulfide and (B) Cell 2 containing polyimide-co-polysulfide containing 35 wt % sulfur.

FIG. 2 shows galvanostatic curves illustrating first cycle capacity results (mAh/g) as a function of voltage (V) at C/10 for Cell 2 containing the copolymer shown in Example 1(c).

FIG. 3 shows galvanostatic curves illustrating the capacity results (mAh/g) as a function of voltage (V) for the first charge-discharge cycle for Cell 3 (dotted line), Cell 4 (thick solid line) and Cell 5 (thin solid line).

FIG. 4 shows galvanostatic curves illustrating the capacity results (mAh/g) as a function of voltage (V) for the first charge-discharge cycle of cell 6 (dotted line) and cell 7 (solid line).

FIG. 5(A) shows the cyclic voltammetry curves of cells 8 (dotted line) and 9 (solid line) containing the active material of Example 1(h), and FIG. 5(B) shows the galvanostatic curves showing the capacity results (mAh/g) as a function of voltage (V) for the first charge-discharge cycle of cells 8 and 9.

FIG. 6 shows the infrared transmission spectra of the active electrode materials shown in Examples 1(b), (c), and (d), the monomers used in the copolymerization, the imide copolymers without added sulfur, and elemental sulfur.

FIG. 7 shows the infrared transmission spectra of the active electrode materials shown in Examples 1(f) and 1(g), the monomers used in the copolymerization, elemental sulfur, and the copolymer without added sulfur.

FIG. 8 shows infrared transmission spectra of the active material shown in Example 1(h), the monomer used in the copolymerization, elemental sulfur, and the copolymer to which no sulfur was added.

FIG. 9 shows the ionic conductivity results (S cm ⁻¹ ) as a function of temperature (K ⁻¹ ) for the copolymers shown in Example 1(c).

FIG. 10 shows the ionic conductivity results (S cm ⁻¹ ) as a function of temperature (K ⁻¹ ) for the copolymer shown in Example 1(d).

11 shows the ionic conductivity results (S cm ⁻¹ ) as a function of temperature (K ⁻¹ ) for the copolymer described in Example 1(g). The ionic conductivity values for the film described in Example 5(c) are shown in (A); the ionic conductivity values for the pressed powder form described in Example 5(d) are shown in (B).

All technical and scientific terms and expressions used herein have the same definitions as commonly understood by a person skilled in the art related to the present technology. Nevertheless, definitions of some of the terms and expressions used are provided below.

As used herein, the term "about" means approximately, in the vicinity, and in the region of. When the term "about" is used in connection with a numerical value, it modifies the numerical value above and below with, for example, a variance of 10% from the nominal value. The term may also take into account experimental error, for example, due to a measuring device or rounding.

Whenever a range of values is mentioned in this application, the lower and upper limits of the range are always included in the definition, unless otherwise stated.

The chemical structures depicted herein are drawn in accordance with standards of the art. Also, where an atom, such as a drawn carbon atom, appears to have incomplete valences, the valences are considered to be satisfied by one or more hydrogen atoms, even if no hydrogen atoms are explicitly drawn.

As used herein, the term "alkyl" or "alkylene" refers to a saturated hydrocarbon group having from 1 to 16 carbon atoms, including straight or branched chain groups. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, tert-butyl, sec-butyl, isobutyl, and the like. When an alkyl group is located between two functional groups, the term alkylene may also be used, such as methylene, ethylene, propylene, and the like. The terms "C _{i -C ii} alkyl" and "C _i -C _ii alkylene" refer to an alkyl or alkylene group having from number "i" to number "ii" carbon atoms, respectively.

As used herein, the term "aryl" or "arylene" refers to an aromatic group having 4n+2 π (pi) electrons (n is an integer from 1 to 3) and 6 to 20 ring atoms in a conjugated monocyclic or polycyclic ring system (fused or non-fused). Polycyclic ring systems contain at least one aromatic ring. The group may be directly bonded or connected through a C ₁ -C ₃ alkyl group. Examples of aryl groups include, but are not limited to, phenyl, benzyl, phenethyl, 1-phenylethyl, tolyl, naphthyl, biphenyl, terphenyl, indenyl, benzocyclooctenyl, benzocycloheptenyl, azulenyl, acenaphthylenyl, fluorenyl, phenanthrenyl, anthracenyl, perylenyl, and the like. When an aryl group is located between two functional groups, the term arylene may also be used. The terms aryl or arylene include substituted or unsubstituted groups. For example, the term "C ₆ -C _n aryl" refers to an aryl group having from 6 to the designated "n" carbon atoms in the ring structure.

The term "substituted" when referring to a group refers to a group in which at least one hydrogen atom has been replaced with a suitable substituent. Non-limiting examples of substituents include cyano, halogen (i.e., F, Cl, Br, or I), amido, nitro, trifluoromethyl, lower alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, lower alkoxy, aryloxy, benzyloxy, benzyl, alkoxycarbonyl, sulfonyl, sulfonate, silane, siloxane, phosphonato, phosphinato, and the like. These substituents can also be substituted where permitted, for example, when the group contains an alkyl group, an alkoxy group, an aryl group, and the like.

The present description relates to the copolymerization of elemental sulfur with organic monomers or the reaction of sulfur with compounds containing disulfide bonds. For example, the present application includes polymers resulting from the copolymerization of sulfur with electrochemically active polyimides. Alternatively, the reaction of sulfur with diimide disulfides results in compounds containing sulfide and organic segments, both of which are electrochemically active. These compounds and polymers not only improve the electrochemical performance of sulfur by reducing or eliminating the dissolution problem, but may also contribute to capacity, given the presence of organic segments that are similarly active in redox reactions. Thus, electrode materials containing the polymers or compounds defined herein can be characterized as hybrid organosulfur cathode materials.

（式中、
Ａは、電子の非局在化を許容する不飽和基、例えば、置換または非置換のアリールおよびヘテロアリール基、ならびにそれらの縮合または非縮合多環式対応物から選択され；
Ｒは、直鎖または分岐鎖Ｃ_２－６アルキレン、直鎖または分岐鎖Ｃ_２－６アルキレンオキシ、直鎖または分岐鎖Ｃ_２－６アルキレングリコール、直鎖または分岐鎖Ｃ_２－６アルキレンオキシＣ_２－６アルキレン、直線状または分岐鎖ポリ（Ｃ_２－６アルキレングリコール）、Ｃ_６－１２アリーレン、Ｃ_３－１２シクロアルキレン、Ｃ_５－１２ヘテロアリーレン、およびＣ_３－１２ヘテロシクロアルキレンから選択される置換または非置換有機連結基であり；
ｍは、ポリマーリンクのジスルフィド結合に挿入された硫黄原子の平均数を表し、ゼロであり得ず、すなわち、ｍ＞０、例えば０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４であり；かつ
ｎは、ポリマー中の単位の平均数を表し、例えば、ｎは２～５００、または５～３００の範囲内であり得る）
によって表される。 For example, the polymer is a copolymer composed of electrochemically active polyimide segments and polysulfide segments of the form -S-(S) _m -S- (m≧1). An example of a polymer is represented by Formula I:

(Wherein,
A is selected from unsaturated groups that allow for electron delocalization, such as substituted or unsubstituted aryl and heteroaryl groups, and their fused or non-fused polycyclic counterparts;
R is a substituted or unsubstituted organic linking group selected from linear or branched C _2-6 alkylene, linear or branched C _2-6 alkyleneoxy, linear or branched C _2-6 alkylene glycol, linear or branched C _2-6 alkyleneoxy C _2-6 alkylene, linear or branched poly(C _2-6 alkylene glycol), C _6-12 arylene, C _3-12 cycloalkylene, C _5-12 heteroarylene, and C _3-12 heterocycloalkylene;
m represents the average number of sulfur atoms inserted into the disulfide bonds of the polymer links and cannot be zero, i.e., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4; and n represents the average number of units in the polymer, e.g., n can be in the range of 2 to 500, or 5 to 300.
It is represented by:

According to one example, A may be selected from benzene, naphthalene, perylene and biphenyl groups.

（式中、Ｒ、ｍおよびｎは、本明細書に定義される通りである）
のポリマーである。 For example, A is a benzene group and the polymer has the formula I(a):

wherein R, m, and n are as defined herein.
It is a polymer of.

By way of further example, R may be selected from the group consisting of benzene, ethylene, propylene, poly(ethylene glycol), poly(propylene glycol), and copolymers of ethylene glycol and propylene glycol.

（式中、ｍおよびｎは、本明細書に定義される通りである）
のポリマーである。 For example, A and R are benzene groups and the polymer has the formula I(b) or I(c):

wherein m and n are as defined herein.
It is a polymer of.

（式中、ＡおよびＲは、本明細書に定義される通りであり、ｍは、化合物のジスルフィド結合に挿入された硫黄原子の平均数を表し、例えば、ｍ＞０、例えば、０＜ｍ≦８、または１≦ｍ≦６、または１≦ｍ≦４である）
である。 According to another example, the active material may rather be a compound of formula II:

wherein A and R are as defined herein, and m represents the average number of sulfur atoms inserted into the disulfide bonds of the compound, e.g., m>0, e.g., 0<m≦8, or 1≦m≦6, or 1≦m≦4.
It is.

（式中、Ｒおよびｍは、本明細書に定義される通りである）
のポリマーである。 For example, A is benzene and the polymer has the formula II(a):

wherein R and m are as defined herein.
It is a polymer of.

（式中、ｍは上記に定義される通りである）
のポリマーである。 For example, R is benzene and the polymer has the formula II(b):

(wherein m is as defined above).
It is a polymer of.

The present application also describes a process for the synthesis of polymers, including organic sulfide hybrids, as defined herein, which comprises the steps of polymerization and sulfurization by reaction with elemental sulfur, these steps being carried out in any order. For example, the process comprises the steps of:
a) polymerization by polycondensation between a dianhydride and a diamine disulfide to form an electrochemically active polyimide; and b) copolymerization of the electrochemically active polyimide with elemental sulfur _S8 to insert a polysulfide segment (of the form -(S) _m- ; m>1).

According to one example, the organic segment of the copolymer is synthesized by polycondensation between pyromellitic dianhydride (1) and 4-aminophenyl disulfide (2) to form a polyimide (3). For example, the polycondensation is carried out at a temperature of about 150° C. The copolymer can be prepared by the polymerization process illustrated in Scheme 1:

あるいは、本願は、以下のステップを含む、本明細書において定義され、有機硫化物ハイブリッドを含むポリマーを合成するためのプロセスを記載する：
ａ）ジアミンジスルフィドと硫黄元素Ｓ_８の重合によって行われる、ポリスルフィドを形成するセグメント（－（Ｓ）_ｍ－の形式；ｍ≧１）の挿入によるアミノ－硫黄コモノマーの合成；および
ｂ）ポリイミドを形成するためのアミノ－硫黄コモノマーと二無水物の重縮合。 According to one example, polysulfide segments (of the form -(S) _m -; m≧1) are then inserted into the disulfide bonds. The insertion can then be carried out by heating the electrochemically active polyimide containing disulfide bonds and elemental sulfur S ₈ at a temperature of 150° C. or higher, or at a temperature of 185° C. or higher, or between 160° C. and 200° C. The heating step opens the elemental sulfur S ₈ ring, allowing the polysulfide segments (of the form -(S) _m -; m≧1) to be inserted into the disulfide bonds to form polysulfides. The insertion of polysulfide segments can be carried out by the process illustrated in Scheme 2, in which the insertion of polysulfide segments (of the form -(S) _m -; m≧1) is carried out into the disulfide bonds of polyimide (3) at 185° C. to obtain polyimide-co-polysulfide (4):

Alternatively, the present application describes a process for synthesizing a polymer comprising an organic sulfide hybrid as defined herein, comprising the following steps:
a) synthesis of amino-sulfur comonomers by polymerization of diamine disulfides with elemental sulfur _S8 , with insertion of segments (of the form -(S) _m- ; m>1) to form polysulfides; and b) polycondensation of amino-sulfur comonomers with dianhydrides to form polyimides.

According to one example, polysulfide segments (of the form -(S) _m -; m≧1) are inserted into the disulfide bonds of diamine disulfides. Insertion can be performed by heating a diamine disulfide comprising elemental sulfur S ₈ and disulfide bonds at a temperature of 150° C. or higher, or at a temperature of 185° C. or higher, or between 160° C. and 200° C. The heating step opens the elemental sulfur S ₈ ring, allowing the polysulfide segments to be inserted into the disulfide bonds to form polysulfides. Insertion of polysulfide segments can be performed by the process illustrated in Scheme 3, in which insertion of polysulfide segments is performed into the disulfide bonds of 4-aminophenyl disulfide (2) at 185° C. to give amino-sulfur comonomer (3):

ここで、ｍおよびｎの値は、反応混合物中の硫黄の質量百分率の関数として決定される。共重合体中の硫黄の質量百分率は、０．１％～９９．９％、例えば、５％～９５％の間で変動し得る。ポリマーは、特に挿入ステップで高い割合の硫黄が含まれている場合に、ジスルフィド結合に挿入されていない、残留する一定量の遊離硫黄元素を含むこともある。 According to one example, polymerization is then carried out by polycondensation between amino-sulfur comonomer (3) and pyromellitic dianhydride (4) to form polyimide-co-polysulfide (5). The polycondensation can be carried out, for example, at a temperature of about 150° C. The polymer can be prepared by the polymerization process illustrated in Scheme 4:

where the values of m and n are determined as a function of the mass percentage of sulfur in the reaction mixture. The mass percentage of sulfur in the copolymer can vary between 0.1% and 99.9%, for example, between 5% and 95%. The polymer may also contain a certain amount of residual free elemental sulfur that is not inserted into disulfide bonds, especially when a high proportion of sulfur is included in the insertion step.

The present application also proposes a positive electrode material comprising a polymer or compound defined herein as an electrochemically active material. According to an example, the positive electrode material may further comprise a conductive material, a binder, or a combination thereof. The electrode material may also comprise free elemental sulfur (S _x ).

Non-limiting examples of conductive materials may include carbon sources such as carbon black, Ketjen™ carbon, Shawinigan carbon, acetylene black, graphite, graphene, carbon fibers (e.g., carbon nanofibers, such as VGCF formed in the gas phase), and carbon nanotubes, or a combination of at least two thereof. For example, the conductive material is a combination of VGCF and Ketjen™ black.

Non-limiting examples of binders include linear, branched and/or cross-linked polyether type polymers, which may be based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), or a combination of the two (or EO/PO copolymers), optionally including cross-linkable units; fluorinated polymers such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); or water-soluble binders, such as styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), hydrogenated NBR (HNBR), epichlorohydrin rubber (CHR), or acrylate rubber (ACM), optionally including carboxymethylcellulose (CMC). For example, the binder is PVDF, which is dissolved in N-methyl-2-pyrrolidone (NMP) when mixed with the other components of the cathode material for application, and the solvent is subsequently removed.

According to one example, the positive electrode material can be applied to a current collector (e.g., aluminum, copper). Alternatively, the positive electrode can be free-standing. For example, the current collector is aluminum.

The present application also proposes an electrochemical cell including at least a positive electrode material, a negative electrode, and an electrolyte as defined herein. The electrolyte is then selected for its compatibility with the various components of the battery. Any type of electrolyte is contemplated, e.g., liquid, gel, or solid electrolytes.

The present application also proposes an electrolyte comprising a polymer as defined herein or a compound as defined herein.

According to one example, the electrolyte is a liquid electrolyte comprising a salt in a solvent. According to one alternative, the electrolyte is a gel electrolyte comprising a salt in a solvent and optionally a solvating polymer. According to another alternative, the electrolyte is a solid polymer electrolyte (SPE) comprising a salt in a solvating polymer.

Compatible electrolytes typically include at least one lithium salt, such as lithium hexafluorophosphate (LiPF ₆ ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF ₄ ), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO ₃ ), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), and the like, and compositions comprising the same dissolved in a non-aqueous (organic) solvent or a solvating polymer. For example, the electrolyte is LiTFSI dissolved in dimethoxyethane (DME) and 1,3-dioxolane (DOL) (DME/DOL), which contains lithium nitrate (1%, LiNO ₃ ).

According to another example, the electrolyte may further include elemental sulfur, an electrolyte binder, a separator, an additive, or a combination of at least two thereof.

For example, the electrolyte binder is PVDF (polyvinylidene fluoride). For example, the electrolyte comprises between 0% and 25% by weight, particularly between 0% and 20% by weight, more particularly between 5% and 15% by weight, even more particularly between 7% and 13% by weight, ideally 10% by weight of the electrolyte binder (upper and lower limits included).

Non-limiting examples of separators may include polyethylene (PE), polypropylene (PP), cellulose, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) and polypropylene-polyethylene-polypropylene (PP/PE/PP) membranes.

According to another example, the electrolyte is a solid polymer electrolyte (SPE) comprising a salt as defined herein in a solvating polymer, the solvating polymer being a polymer as defined herein. For example, the SPE comprises between 60% and 95% by weight, in particular between 65% and 90% by weight, more particularly between 70% and 85% by weight, even more particularly between 75% and 85% by weight, ideally 80% by weight of a polymer as defined herein (including upper and lower limits). For example, the SPE comprises between 5% and 40% by weight, in particular between 10% and 35% by weight, more particularly between 15% and 30% by weight, more particularly between 15% and 25% by weight, ideally 20% by weight of a salt (including upper and lower limits).

The present application also contemplates an electrochemical cell comprising a cathode, an anode and an electrolyte as defined herein. The present application also contemplates an electrochemical cell comprising a cathode, an anode and an electrolyte, where the electrolyte and the cathode are as defined herein.

According to another aspect, the electrochemical cell of the present application is included in a lithium battery. For example, the lithium battery is a lithium-sulfur battery.

According to another aspect, the electrochemical cells of the present application are used in portable devices, such as mobile phones, cameras, tablets or laptops, in electric or hybrid vehicles, or in renewable energy storage.

The following examples are illustrative and should not be construed as further limiting the scope of the invention described.

Example 1 - Synthesis of Organosulfur Hybrid Active Electrode Material a) Copolymerization of Pyromellitic Dianhydride, 4-Aminophenyl Disulfide and Sulfur (5 wt%) The synthesis of the electrode material was carried out in a 25 mL flask equipped with a magnetic bar. The active electrode material was prepared by combining 0.085 g of elemental sulfur _S8 (0.33 mmol) and 0.745 g of 4-aminophenyl disulfide (3 mmol). The flask was then sealed and placed under a flow of inert gas ( _N2 ). Once the flask was purged of air, the mixture was heated to a temperature of 185°C under constant stirring at 500 rpm for about 30 minutes until a homogenous liquid was obtained. The mixture was then cooled to a temperature of 150°C, after which the sealed cap was removed and 0.654 g of pyromellitic dianhydride (3 mmol) previously dissolved in the organic solvent N,N-dimethylformamide (DMF) was added. The flask containing the mixture was then covered and kept at a temperature of 150° C. under stirring (500 rpm) for 26 hours. The mixture was then cooled. The solid thus produced was collected, washed with tetrahydrofuran (THF) and dried under vacuum in order to sublimate the unreacted sulfur. Finally, the percentage of sulfur in the produced active electrode material (polymer) was determined by elemental analysis. The active electrode material in this example contained 5% sulfur.

b) Copolymerization of pyromellitic dianhydride, 4-aminophenyl disulfide and sulfur (25 wt%). The synthesis of this active electrode material was carried out according to the process shown in Example 1(a). The masses of elemental sulfur S ₈ and 4-aminophenyl disulfide for the synthesis of the amino-sulfur comonomer were 0.309 g (1.206 mmol) and 0.447 g (1.8 mmol), respectively, and the mass of pyromellitic dianhydride for the polycondensation was 0.393 g (1.8 mmol). The active electrode material thus produced contained 25 wt% sulfur as determined by elemental analysis.

c) Copolymerization of pyromellitic dianhydride, 4-aminophenyl disulfide and sulfur (35 wt%). The synthesis of this active electrode material was carried out according to the process shown in Example 1(a). The masses of elemental sulfur S ₈ and 4-aminophenyl disulfide for the synthesis of the amino-sulfur comonomer were 1.033 g (4.026 mmol) and 1 g (4.026 mmol), respectively, and the mass of pyromellitic dianhydride for the polycondensation was 0.878 g (4.026 mmol). The active electrode material thus produced contained 35 wt% sulfur as determined by elemental analysis.

d) Copolymerization of pyromellitic dianhydride, 4-aminophenyl disulfide and sulfur (63 wt%). The synthesis of this active electrode material was carried out according to the process shown in Example 1(a). The masses of elemental sulfur S ₈ and 4-aminophenyl disulfide for the synthesis of the amino-sulfur comonomer were 2.463 g (9.6 mmol) and 0.397 g (1.6 mmol), respectively, and the mass of pyromellitic dianhydride for the polycondensation was 0.349 g (1.6 mmol). The active electrode material thus obtained contained 63 wt% sulfur as determined by elemental analysis.

e) Copolymerization of pyromellitic dianhydride, 4-aminophenyl disulfide and sulfur (95 wt%). The synthesis of this active electrode material was carried out according to the process shown in Example 1(a). The masses of elemental sulfur S ₈ and 4-aminophenyl disulfide for the synthesis of the amino-sulfur comonomer were 8.978 g (35 mmol) and 0.248 g (1 mmol), respectively, and the mass of pyromellitic dianhydride for the polycondensation was 0.218 g (1 mmol). The active electrode material thus produced contained 95 wt% sulfur as determined by elemental analysis.

電極材料の合成を、マグネチックバーを装備した２５ｍＬフラスコ内で行った。活性電極材料を、０．９２３ｇの硫黄元素Ｓ_８（３．６ｍｍｏｌ）と０．４４７ｇの４－アミノフェニルジスルフィド（１．８ｍｍｏｌ）を合わせることにより調製した。次に、フラスコを密閉し、不活性ガス（Ｎ_２）流下に置いた。フラスコの空気がパージされたら、混合物を、均一な液体が得られるまで約３０分間、５００ｒｐｍの一定の撹拌下で１８５℃の温度に加熱した。次に、混合物を１５０℃の温度に冷却した後、密閉したキャップを取り外して、事前に有機溶媒であるＮ，Ｎ－ジメチルホルムアミド（ＤＭＦ）に溶解させた０．４８３ｇの１，４，５，８－ナフタレンテトラカルボン酸二無水物（１．８ｍｍｏｌ）を添加した。次に、混合物を含有するフラスコに覆いをし、撹拌下（５００ｒｐｍ）で２６時間、１５０℃の温度で保持した。次に、混合物を冷却した。このようにして生成された固体を集め、テトラヒドロフラン（ＴＨＦ）で洗浄し、未反応の硫黄を昇華させるために真空下で乾燥させた。最後に、生成された活性電極材料（ポリマー）中の硫黄の割合を元素分析によって測定した。この実施例の活性電極材料は、２０％の硫黄を含んでいた。 f) Copolymerization of 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4-aminophenyl disulfide and sulfur (20% by weight)

The synthesis of the electrode material was carried out in a 25 mL flask equipped with a magnetic bar. The active electrode material was prepared by combining 0.923 g of elemental sulfur S ₈ (3.6 mmol) and 0.447 g of 4-aminophenyl disulfide (1.8 mmol). The flask was then sealed and placed under a flow of inert gas (N ₂ ). Once the flask was purged of air, the mixture was heated to a temperature of 185° C. under constant stirring at 500 rpm for approximately 30 minutes until a homogenous liquid was obtained. The mixture was then cooled to a temperature of 150° C., after which the sealed cap was removed and 0.483 g of 1,4,5,8-naphthalenetetracarboxylic dianhydride (1.8 mmol) previously dissolved in the organic solvent N,N-dimethylformamide (DMF) was added. The flask containing the mixture was then covered and held at a temperature of 150° C. under stirring (500 rpm) for 26 hours. The mixture was then cooled. The solid thus produced was collected, washed with tetrahydrofuran (THF), and dried under vacuum to sublimate the unreacted sulfur. Finally, the percentage of sulfur in the produced active electrode material (polymer) was determined by elemental analysis. The active electrode material in this example contained 20% sulfur.

g) Copolymerization of 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4-aminophenyl disulfide and sulfur (30 wt%). The synthesis of the active electrode material was carried out according to the process shown in Example 1(f). The masses of elemental sulfur S ₈ and 4-aminophenyl disulfide for the synthesis of the amino-sulfur comonomer were 2.052 g (8 mmol) and 1.987 g (8 mmol), respectively, and the mass of 1,4,5,8-naphthalenetetracarboxylic dianhydride for the polycondensation was 2.145 g (8 mmol). The active electrode material thus produced contained 30 wt% sulfur as determined by elemental analysis.

h) Copolymerization of pyromellitic dianhydride and cystamine by polycondensation followed by insertion of sulfur (20 wt%). The synthesis of the copolymer was carried out in a 100 mL flask equipped with a magnetic bar. This material was prepared by combining 7.614 g of cystamine dihydrochloride (0.5 mol) and 10.91 g of pyromellitic dianhydride (0.5 mol). The mixture was then heated to a temperature of 150° C. under stirring (500 rpm) for 26 hours. The mixture was then cooled. The solid thus formed was collected and washed with tetrahydrofuran (THF). 1.204 g of this copolymer was then dispersed in NMP and 1.856 g of elemental sulfur S ₈ (50 wt%) was added. The flask was then sealed and placed under a flow of inert gas (N ₂ ). Once the flask was purged of air, the mixture was heated to a temperature of 185° C. under constant stirring at 500 rpm for about 20 hours. The mixture was then cooled. The solid thus produced was collected, washed with tetrahydrofuran (THF) and dried under vacuum to sublimate the unreacted sulfur. Finally, the percentage of sulfur in the produced active electrode material (polymer) was determined by elemental analysis. The active electrode material in this example contained 20% sulfur.

Example 2 - Preparation of electrochemical cells a) Cathode The cathode material is composed of 60 wt% hybrid organosulfide electrode material, i.e. polyimide-co-polysulfide of Example 1, or polyimide disulfide (reference), 30 wt% conductive carbon (15% VGCF and 15% Ketjen™ 600 carbon) and 10 wt% binder, i.e. polyvinylidene fluoride (PVDF) dissolved in N-methyl-2-pyrrolidone (NMP). The current collector is aluminum. The solvent is evaporated after application.

b) Electrolyte The electrolyte consists of a 1 M solution of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dissolved in a mixture of dimethoxyethane (DME) and 1,3-dioxolane (DME/DOL), and lithium nitrate (1%, LiNO ₃ ).

c) Anode The anode consists of metallic lithium in the form of a thin film.

d) Electrochemical Cell A cell is therefore prepared with the following components:
Li/electrolyte/cathode/Al

Cell 1
Cell 1 contains a reference cathode comprising the disulfide polyimide shown in Example 2(a), an electrolyte shown in Example 2(b), and an anode composed of metallic lithium shown in Example 2(c).

Cell 2
Cell 2 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(c), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 3
Cell 3 includes a cathode as shown in Example 2(a) containing the electrode material of Example 1(d), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 4
Cell 4 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(e), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 5
Cell 5 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(b), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 6
Cell 6 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(f), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 7
Cell 7 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(g), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 8
Cell 8 includes a cathode as shown in Example 2(a) containing the electrode material (without added sulfur) of Example 1(h), an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Cell 9
Cell 9 includes a cathode as shown in Example 2(a) comprising the electrode material of Example 1(a) containing 20% by weight sulfur, an electrolyte as shown in Example 2(b), and an anode composed of metallic lithium as shown in Example 2(c).

Example 3 - Electrochemical properties Electrochemical measurements were carried out on the electrochemical cell of Example 2(d). As demonstrated in Figure 1, the presence of sulfur inserted in the disulfide bonds makes it possible to obtain higher performance materials with improved capacity and cyclability. Figures 1(A) and 1(B) show the results of capacity and capacity retention as a function of cycle number for Cell 1 (reference) and Cell 2, respectively. Indeed, by comparing the presented results, a significant improvement in capacity and percentage of capacity retention can be observed for Cell 2 compared to Cell 1.

Figure 2 shows the first cycle capacity results as a function of voltage at C/10 for cell 2. The polymer contribution to the capacity of the new material can be confirmed by the presence of a plateau at about 2.2 V. Cell 2 obtains a first discharge capacity of 290 mAh g ^-1 at C/10 and a capacity retention of 65% after 100 cycles at C/2.

Figure 3 shows the first charge-discharge curves of cells 3-5 at C/10. The initial capacity varies depending on the nature of the active materials. The capacities obtained for cells 3, 4 and 5 are 407 mAh g ^-1 , 570 mAh g ^-1 and 277 mAh g ^-1 , respectively.

Figure 4 shows the first cycle capacity results at C/10 as a function of voltage for cells 6 and 7. The sulfur contribution to the capacity of the new material can be confirmed by the presence of a plateau around 2.05 V. Cell 6 obtains a first discharge capacity of 305 mAh g ^-1 at C/10 and a capacity retention of 91% after 50 cycles at C/2. For cell 7, the first discharge capacity is 443 mAh g ^-1 at C/10 and a capacity retention of 75% after 50 cycles.

Figure 5(a) shows the cyclic voltammograms of cells 8 and 9. It is possible to see the effect of the addition of sulfur on the intensity of the oxidation and reduction peaks. Moreover, as can be observed in Figure 5(b), an increase in capacity is obtained by adding sulfur. Cell 8 obtains an initial discharge capacity of 138 mAh g- ¹ at C/10 and a capacity retention of 37% after 100 cycles at C/2. For cell 9, the capacity obtained at the first discharge is 195 mAh g ^-1 at C/10, with a capacity retention of 50% after 100 cycles.

Example 4 - Characterization and Determination of Material Composition The composition of the materials presented in Example 1 was determined using transmission infrared spectroscopy. Figure 6 shows the infrared transmission spectra of the active electrode materials shown in Examples 1(b), (c), and (d) as well as the spectra of the monomers used during copolymerization, the infrared transmission spectrum of the imide copolymer without added sulfur, and the infrared transmission spectrum of elemental sulfur.

Figure 7 shows the infrared transmission spectra of the active electrode materials shown in Examples 1(f) and 1(g), as well as the spectra of the monomers used in the copolymerization, the infrared transmission spectrum of elemental sulfur, and the infrared transmission spectrum of a copolymer that does not contain sulfur.

Figure 8 shows the infrared transmission spectrum of the active electrode material shown in Example 1(h), as well as the spectrum of the monomer used in the copolymerization, the infrared transmission spectrum of elemental sulfur, and the infrared transmission spectrum of the copolymer without added sulfur.

Example 5 - Ionic conductivity a) Measurement of the ionic conductivity of the material shown in Example 1(c) Ionic conductivity results were obtained for the copolymer shown in Example 1(c). To do this, the copolymer shown in Example 1(c) was mixed with a lithium salt (LiTFSI) and a binder (PVDF) in an organic solvent (NMP). A homogeneous dispersion was applied to a stainless steel foil with a thickness of 27 μm. The film was then dried at a temperature of 120° C. for 16 hours. The NMP evaporated and a ratio (copolymer:LiTFSI:PVDF) of 70:20:10 (by weight percentage) was obtained.

The resulting film was then placed between two stainless steel electrodes and assembled into a coin cell to measure the ionic conductivity. Electrochemical impedance spectroscopy measurements were performed between 800 kHz and 100 Hz at various temperatures (25°C, 40°C, 60°C and 80°C).

9 graph shows the measured conductivity values as a function of temperature. A maximum value of 3.06×10 ⁻⁶ S·cm ⁻¹ was obtained at a temperature of 80° C.

b) Measurement of the ionic conductivity of the material shown in Example 1(d) The conductivity as a function of temperature of the sulfur-containing copolymer shown in Example 1(d) was measured using the method and ratios shown in Example 5(a). The ionic conductivity results are shown in Figure 10. A maximum of 1.12 x ^10-8 S cm- ¹ was obtained at a temperature of 80°C.

c) Measurement of the ionic conductivity of the material shown in Example 1(g) The conductivity as a function of temperature of the sulfur-containing copolymer shown in Example 1(g) was measured using the method and ratios shown in Example 5(a). The results are shown in Figure 11(A). A maximum of 6.43 x ^10-9 S cm- ¹ was obtained at a temperature of 80°C.

d) Measurement of the ionic conductivity of the material shown in Example 1(g) The ionic conductivity was measured a second time on the sulfur-containing copolymer shown in Example 1(g). To do this, the sulfur-containing copolymer shown in Example 1(g) was mixed with 20% by weight of a lithium salt (LiTFSI). This solid mixture was pressed between two stainless steel electrodes at a temperature of 150° C. for 30 minutes. Electrochemical impedance spectroscopy measurements were then performed between 800 kHz and 100 Hz at various temperatures (25° C., 40° C., 60° C. and 80° C.). The results are shown in FIG. 11(B). A maximum ionic conductivity of 1.1×10 ⁻⁵ S·cm ⁻¹ was obtained at a temperature of 40° C.

Numerous modifications can be made to any of the above embodiments without departing from the scope of the invention as contemplated. Any reference, patent, or scientific literature documents mentioned in this application are hereby incorporated by reference in their entirety for all purposes.

Claims (19)

Compound of Formula II:

[Wherein,
A is an unsaturated group that allows for electron delocalization selected from substituted or unsubstituted aryl and heteroaryl groups, and their fused or non-fused polycyclic equivalents;
R is an organic linking group selected from unsubstituted linear or branched C _2-6 alkylene, substituted or unsubstituted linear or branched C 2-6 alkyleneoxy, substituted or unsubstituted linear or branched C _2-6 alkylene glycol, substituted or unsubstituted linear or branched C _2-6 alkyleneoxy C _2-6 alkylene, substituted or unsubstituted linear or branched poly(C _2-6 alkylene glycol), substituted or unsubstituted C _6-12 arylene, substituted _or unsubstituted C _3-12 cycloalkylene , substituted or unsubstituted C _5-12 heteroarylene, and substituted or unsubstituted C _3-12 heterocycloalkylene;
m represents the number of sulfur atoms inserted into the disulfide bond of the compound and is not 0, i.e., m>0. The compound according to claim 1, wherein m is 0<m≦8, or 1≦m≦6, or 1≦m≦4. The compound according to claim 1 or 2, wherein R is selected from the group consisting of benzene, ethylene, propylene, poly(ethylene glycol), poly(propylene glycol), and copolymers of ethylene glycol and propylene glycol. The compound according to any one of claims 1 to 3, wherein A is selected from benzene, naphthalene, perylene, and biphenyl groups. The compound has formula II(a):

wherein R and m are as defined in any one of claims 1 to 3.
5. The compound according to claim 1 , The compound has formula II(b):

wherein m is as defined in claim 1 or 2.
5. The compound according to claim 1 , An electrode material comprising a compound as defined in any one of claims 1 to 6 and optionally elemental sulfur, a conductive material, a binder, or a combination of at least two thereof. The electrode material of claim 7, wherein the conductive material is selected from carbon black, Ketjen™ carbon, Shawinigan carbon, acetylene black, graphite, graphene, carbon fiber, and carbon nanotubes, or a combination of at least two thereof. 9. An electrode material according to claim 7 or 8, wherein the binder is a polymeric binder of the polyether type or a fluorinated polymer. The binder is
a polyether type polymeric binder selected from linear , branched and/or crosslinked, based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and mixtures of the two ( or EO/PO copolymers), optionally containing crosslinkable units;
PVDF (polyvinylidene fluoride) and PTFE (polytetrafluoroethylene); or
SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), and ACM (acrylate rubber), optionally containing CMC (carboxymethyl cellulose);
The electrode material according to claim 7 or 8 . A positive electrode comprising the electrode material according to any one of claims 7 to 10 applied to a current collector. An electrolyte comprising a compound defined in any one of claims 1 to 6 and optionally elemental sulfur. The electrolyte of claim 12, wherein the electrolyte is a liquid electrolyte comprising a salt in a solvent, or a gel electrolyte comprising a salt in a solvent and optionally a solvating polymer, or a solid polymer electrolyte (SPE) comprising a salt in a solvating polymer. The electrolyte of claim 13, wherein the solvent of the liquid or gel electrolyte is a polar aprotic solvent selected from ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), gamma-butyrolactone (gamma-BL), vinylene carbonate (VC), methyl butyrate (MB), gamma-valerolactone (gamma-VL), 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 2-methyltetrahydrofuran, dimethylsulfoxide, formamide, acetamide, dimethylformamide, dioxolane, acetonitrile, propylnitrile, nitromethane, ethyl monoglyme, trimethoxymethane, sulfolane, methylsulfolane, tetrahydrofuran, and mixtures thereof. The salt of the liquid, gel or solid polymer electrolyte may be selected from the group consisting of lithium hexafluorophosphate (LiPF ₆ ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium tetrafluoroborate (LiBF ₄ ), lithium bis(oxalato)borate (LiBOB), lithium nitrate (LiNO ₃ ), lithium chloride (LiCl), lithium bromide (LiBr), lithium fluoride (LiF), lithium perchlorate (LiClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), lithium trifluoromethanesulfonate (LiSO ₃ CF ₃ ) (LiTf), lithium fluoroalkyl phosphate Li[ _PF3 ( _{CF2CF3 ) 3} ] (LiFAP), lithium tetrakis(trifluoroacetoxy)borate Li[B( _OCOCF3 ) ₄ ] (LiTFAB), lithium bis(1,2-benzenediolato(2-)-O, _O ')borate Li[B( _C6O2 ) ₂ ] (LBBB) and combinations thereof. An electrolyte according to any one of claims 12 to 15, wherein the compound is an additive. The electrolyte of any one of claims 12 to 16, wherein the electrolyte further comprises an electrolyte binder. An electrochemical cell comprising a cathode, an electrolyte, and an anode,
The cathode comprises an electrode material as defined in any one of claims 7 to 10:
The cathode is a positive electrode as defined in claim 11;
the electrolyte is as defined in any one of claims 12 to 17; or the cathode is a positive electrode and is as defined in claim 11 and the electrolyte is as defined in any one of claims 12 to 17.
Electrochemical cell. A lithium battery comprising an electrochemical cell as defined in claim 18.

Images